Page 231 - Understanding Psychology

Gamma rays
10–5 10–3
X rays
10–1
Radar
Broadcast AC bands circuits
Figure 8.6
400
Visible light
500 600
Ultra- Infrared violet rays rays
700
White light
1011 1013 Wavelength in nanometers (billionths of a meter)
The Electromagnetic Spectrum
1015 1017
101 103
105
107 109
Light is the visible portion of the electromagnetic spectrum. When the wavelengths in white light are separated, the visual effect is an array of colors because different wavelengths are seen as different colors. Why are we able to see the wavelengths of the visible spectrum?
object, such as an eraser, close to your eyes. Without moving it, look at the eraser first with one eye, then with the other. You will see a difference in the two images because of the different viewpoint each eye has. When you open both eyes, you will no longer see the difference but will in- stead see the object as solid and three-dimensional, if you have good binocular vision.
Retinal disparity is essential to your sense of depth perception. The brain interprets a large retinal disparity (a large difference between what the right eye and what the left eye are seeing) to mean that an object is nearby. The brain interprets a small retinal disparity (not much difference between the images the left and right eyes receive) to mean a distant object.
PSYCHOLOGY
Student Web Activity
Visit the Understanding Psychology Web site at psychology.glencoe.com and click on Chapter 8— Student Web Activities for an activity on sensation and perception.
Prism
Chapter 8 / Sensation and Perception 217